Morag Tong

The Morag Tong is the Dunmer assassins guild. Please don't confuse them with the Empire's Dark Brotherhood. The Morag Tong prides itself on the fact that it operates within the law, rather than being a law unto itself. If you manage to get a death warrant because of some mayhem that you committed in a fit of pique, you're hosed. The Morag Tong WILL NOT fix it for you. Either spend the rest of the game dodging guards and having most people refuse to talk to you or reload/start over.

Members of factions receive different types of welcomes from members of other factions, depending on how they get along. The formula is (Faction Reaction * 5)*(0.5 +(Faction Rank *0.5)). In plain terms, this means that as you attain higher ranks in your faction, people with negative modifiers will like you less and people with positive modifiers will like you more. This does not mean that everyone will start attacking you on sight, nor does it mean that they are going to fall all over themselves to be helpful. It does, however, modify their initial disposition toward you. This initial disposition will be further modified by your Personality, your overall reputation, your Criminal Status, whether or not you are Diseased, what kinds of favors you have done for the faction you're dealing with, etc. The other person may wind up liking you a lot or not liking you at all, but your faction and rank can impose a serious modifier.

Morag Tong Reactions to Other Factions
Hated Enemy
Beloved Ally (+3)
      everyone else     Morag Tong

There you go. The Morag Tong is officially above politics. They are completely indifferent to all factions and all factions are completely indifferent to them. They hate members of the Dark Brotherhood, but that is not a functioning faction in Morrowind.

Advancement within the Morag Tong will depend upon your skill level in three of the following skills:

The Morag Tong's rank structure:

Rank Speed Agility One required Skill at Two other required Skills at Minimum Faction Reputation
1 - Associate 30 30 0 0 0
2 - Blind Thrall 30 30 10 0 10
3 - Thrall 30 30 20 0 20
4 - White Thrall 30 30 30 5 30
5 - Thinker 30 30 40 10 40
6 - Brother 31 31 50 15 50
7 - Knower 32 32 60 20 60
8 - Master 33 33 70 25 80
9 - Exalted Master 34 34 80 30 100
10 - Grandmaster 35 35 90 35 125

Of course, these promotions don't come just based on your skills. You must perform quests to gain reputation and rank within the Temple. You will typically receive 5 points of faction reputation for each successfully completed quest. Just ask about "duties" to anyone who has it in their conversation threads. There are a few Morag Tong quest givers, but they all offer the same quests (called "writs"), with the exception of Grandmaster Hlaalu, who offers "special duties" and the four "Grandmaster Writs" that you can undertake when you have achieved that rank and after you have defeated Dagoth Ur. You may get writs from:

Typically, each rank requires two or three successfully completed quests in addition to the minimum stat and skills requirements.

Finding the Morag Tong

For other factions, it's pretty much a matter of presenting yourself at one of the Guildhalls or Council Chambers and saying "I want to join." Joining the Morag Tong requires that you find the one person in the game who can allow you to join and no one is going to tell you where that person is (except me, of course).

You'll find Grandmaster Hlaalu in a hidden area (that's what it's called: "Hidden Area") in the Storage area of the Arena Canton in Vivec. Go down to the Canalworks and you'll see the storage area at the end. Go through the door and the trapdoor will be in the corner of the right-hand storage room. There are three rats in this area that respawn, so keep a weapon handy when you enter. Grandmaster Hlaalu will be upstairs from the main part of the guildhall. If you are a member of the Morag Tong, you may use any of the three beds in the room before the Grandmaster's, but sleeping in any others will get you expelled and a small bounty (5 golds, I think) placed on your head.

On the bright side of the equation, you can actually get a Morag Tong writ taken out on yourself. You have to do something pretty stupid to set the proper flag, though. Why do I say "on the bright side"? Simple. No one at Bethesda ever enabled the random assassins who were supposed to execute that writ. If you actually talk to Morag Tong members under the proper conditions, their dispositions and fight modifiers will change and they will attack you, but no assassins coming hunting for you. The patch did not set this script.

In addition to being the only person that can let you in, Hlaalu will also give you your first writ: Feruren Oran, Spellsword, Elven Nations Cornerclub, Hlaalu Canton, Vivec.

What makes this tricky is that this is a public execution and his friends (everyone in the club) will attack you if they see you attack him. Best strategy is to taunt him into attacking you or have a VERY good Sneak skill or Chameleon/Invisibility spell and get out quickly. Consider this your rite of passage as there is no fee or reputation boost. You're just in.